COMMUNITY FORUM

Finding electrical box in old ceiling

I just bought an old house. I'm pretty sure that the ceiling has been replaced and the ceiling light fixture box has been covered up. Is there any type of device that would let me know if there is an fixture box up there, without me tearing into the ceiling? There is no attic, so that's not an option. There is a wall switch on the wall but I can not determine what it operates. May this was the switch that originally operated the fixture. ??

The old box might have been removed and/or no wire or inactive wires to it. For example if was orginally K&T then might have been left in place, but abonded. And to use it all new wirings would have to be run.

If it was pre electric then there might have only been wall sconces.

Most likely the switch controls one or more of the receptacles. You will have to check each receptacle in the room and both halves of duplex receptacles.

Or the switch might have been abonded. With older homes it is realy hard to prodict what you might find. Speically if there have been 'creative people" working on it.

As to finding it there are a couple of tricks that can be used.

A metal detector should find the box, but it will also find the nails in the ceiling.

Some stud finders have a hot wire feature and can trace hot wires in the ceiling, but they don't always have enough range and also se don't know if there is any not wires.

And there are tone tracers. But you need to have the other end of the wire and we don't know where that is? (What is in the swtich box? Does it have 2 or 4 or more cables or sets of wires).

A trick with a toner (bird dog) is to turn the switch on, then hold the toner above, below and on the sides of the switch box trying to find a steady tone. IF a tone is found, you can sometimes follow it to the ceiling. This probably will not work if the wiring method was BX (flexible metal encased wiring). IF the wiring was left intact AND the ends are still exposed at the box, a toner may be able to find the box buried in the ceiling. Again this is an IF.

Sometimes during a renovation the switch is left in place as a dummy because a DIYer does not replace the "in the wall box" with the smaller size one.